@@ -4,6 +4,7 @@ mcp25xxfd-objs += mcp25xxfd_can.o
mcp25xxfd-objs += mcp25xxfd_can_fifo.o
mcp25xxfd-objs += mcp25xxfd_can_int.o
mcp25xxfd-objs += mcp25xxfd_can_rx.o
+mcp25xxfd-objs += mcp25xxfd_can_tx.o
mcp25xxfd-objs += mcp25xxfd_cmd.o
mcp25xxfd-objs += mcp25xxfd_crc.o
mcp25xxfd-objs += mcp25xxfd_ecc.o
@@ -20,6 +20,7 @@
#include "mcp25xxfd_can_fifo.h"
#include "mcp25xxfd_can_int.h"
#include "mcp25xxfd_can_priv.h"
+#include "mcp25xxfd_can_tx.h"
#include "mcp25xxfd_can.h"
#include "mcp25xxfd_cmd.h"
#include "mcp25xxfd_int.h"
@@ -395,6 +396,10 @@ static int mcp25xxfd_can_open(struct net_device *net)
if (ret)
goto out_int;
+ /* start the tx_queue */
+ mcp25xxfd_can_tx_queue_manage(cpriv,
+ MCP25XXFD_CAN_TX_QUEUE_STATE_STARTED);
+
return 0;
out_int:
@@ -425,6 +430,10 @@ static int mcp25xxfd_can_stop(struct net_device *net)
struct mcp25xxfd_priv *priv = cpriv->priv;
struct spi_device *spi = priv->spi;
+ /* stop transmit queue */
+ mcp25xxfd_can_tx_queue_manage(cpriv,
+ MCP25XXFD_CAN_TX_QUEUE_STATE_STOPPED);
+
/* shutdown the can controller */
mcp25xxfd_can_shutdown(cpriv);
@@ -448,6 +457,7 @@ static int mcp25xxfd_can_stop(struct net_device *net)
static const struct net_device_ops mcp25xxfd_netdev_ops = {
.ndo_open = mcp25xxfd_can_open,
.ndo_stop = mcp25xxfd_can_stop,
+ .ndo_start_xmit = mcp25xxfd_can_tx_start_xmit,
.ndo_change_mtu = can_change_mtu,
};
@@ -22,12 +22,13 @@ int mcp25xxfd_can_targetmode(struct mcp25xxfd_can_priv *cpriv)
static inline
void mcp25xxfd_can_queue_frame(struct mcp25xxfd_can_priv *cpriv,
- s32 fifo, u16 ts)
+ s32 fifo, u16 ts, bool is_rx)
{
int idx = cpriv->fifos.submit_queue_count;
cpriv->fifos.submit_queue[idx].fifo = fifo;
cpriv->fifos.submit_queue[idx].ts = ts;
+ cpriv->fifos.submit_queue[idx].is_rx = is_rx;
cpriv->fifos.submit_queue_count++;
}
@@ -5,8 +5,6 @@
* Copyright 2019 Martin Sperl <kernel@martin.sperl.org>
*/
-/* here we define and configure the fifo layout */
-
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/spi/spi.h>
@@ -14,6 +12,7 @@
#include "mcp25xxfd_can.h"
#include "mcp25xxfd_can_fifo.h"
#include "mcp25xxfd_can_priv.h"
+#include "mcp25xxfd_can_tx.h"
#include "mcp25xxfd_cmd.h"
static int mcp25xxfd_can_fifo_get_address(struct mcp25xxfd_can_priv *cpriv)
@@ -55,6 +54,15 @@ static int mcp25xxfd_can_fifo_setup_config(struct mcp25xxfd_can_priv *cpriv,
c > 0; i++, f++, p--, c--) {
val = (c > 1) ? flags : flags_last;
+ /* are we in tx mode? */
+ if (flags & MCP25XXFD_CAN_FIFOCON_TXEN) {
+ cpriv->fifos.info[f].is_rx = false;
+ cpriv->fifos.info[f].priority = p;
+ val |= (p << MCP25XXFD_CAN_FIFOCON_TXPRI_SHIFT);
+ } else {
+ cpriv->fifos.info[f].is_rx = true;
+ }
+
/* write the config to the controller in one go */
ret = mcp25xxfd_cmd_write(cpriv->priv->spi,
MCP25XXFD_CAN_FIFOCON(f), val);
@@ -65,6 +73,27 @@ static int mcp25xxfd_can_fifo_setup_config(struct mcp25xxfd_can_priv *cpriv,
return 0;
}
+static int mcp25xxfd_can_fifo_setup_tx(struct mcp25xxfd_can_priv *cpriv)
+{
+ u32 tx_flags = MCP25XXFD_CAN_FIFOCON_FRESET | /* reset FIFO */
+ MCP25XXFD_CAN_FIFOCON_TXEN | /* a tx FIFO */
+ MCP25XXFD_CAN_FIFOCON_TXATIE | /* state in txatif */
+ (cpriv->fifos.payload_mode <<
+ MCP25XXFD_CAN_FIFOCON_PLSIZE_SHIFT) | /* paylod size */
+ (0 << MCP25XXFD_CAN_FIFOCON_FSIZE_SHIFT); /* 1 FIFO deep */
+
+ /* handle oneshot/three-shot */
+ if (cpriv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT)
+ tx_flags |= MCP25XXFD_CAN_FIFOCON_TXAT_ONE_SHOT <<
+ MCP25XXFD_CAN_FIFOCON_TXAT_SHIFT;
+ else
+ tx_flags |= MCP25XXFD_CAN_FIFOCON_TXAT_UNLIMITED <<
+ MCP25XXFD_CAN_FIFOCON_TXAT_SHIFT;
+
+ return mcp25xxfd_can_fifo_setup_config(cpriv, &cpriv->fifos.tx,
+ tx_flags, tx_flags);
+}
+
static int mcp25xxfd_can_fifo_setup_rx(struct mcp25xxfd_can_priv *cpriv)
{
u32 rx_flags = MCP25XXFD_CAN_FIFOCON_FRESET | /* reset FIFO */
@@ -106,7 +135,7 @@ static int mcp25xxfd_can_fifo_setup_rxfilter(struct mcp25xxfd_can_priv *cpriv)
static int mcp25xxfd_can_fifo_compute(struct mcp25xxfd_can_priv *cpriv)
{
- int rx_memory_available;
+ int tef_memory_used, tx_memory_used, rx_memory_available;
switch (cpriv->can.dev->mtu) {
case CAN_MTU:
@@ -114,23 +143,48 @@ static int mcp25xxfd_can_fifo_compute(struct mcp25xxfd_can_priv *cpriv)
cpriv->fifos.payload_size = 8;
cpriv->fifos.payload_mode = MCP25XXFD_CAN_TXQCON_PLSIZE_8;
+ /* 7 tx fifos */
+ cpriv->fifos.tx.count = 7;
+
break;
case CANFD_MTU:
/* MTU is 64 */
cpriv->fifos.payload_size = 64;
cpriv->fifos.payload_mode = MCP25XXFD_CAN_TXQCON_PLSIZE_64;
+ /* 7 tx fifos */
+ cpriv->fifos.tx.count = 7;
+
break;
default:
return -EINVAL;
}
/* compute effective sizes */
+ cpriv->fifos.tef.size = sizeof(struct mcp25xxfd_can_obj_tef);
+ cpriv->fifos.tx.size = sizeof(struct mcp25xxfd_can_obj_tx) +
+ cpriv->fifos.payload_size;
cpriv->fifos.rx.size = sizeof(struct mcp25xxfd_can_obj_rx) +
cpriv->fifos.payload_size;
+ /* set tef fifos to the number of tx fifos */
+ cpriv->fifos.tef.count = cpriv->fifos.tx.count;
+
+ /* compute size of the tx fifos and TEF */
+ tx_memory_used = cpriv->fifos.tx.count * cpriv->fifos.tx.size;
+ tef_memory_used = cpriv->fifos.tef.count * cpriv->fifos.tef.size;
+
/* calculate evailable memory for RX_fifos */
- rx_memory_available = MCP25XXFD_SRAM_SIZE;
+ rx_memory_available = MCP25XXFD_SRAM_SIZE - tx_memory_used -
+ tef_memory_used;
+
+ /* we need at least one RX Frame */
+ if (rx_memory_available < cpriv->fifos.rx.size) {
+ netdev_err(cpriv->can.dev,
+ "Configured %i tx-fifos exceeds available memory already\n",
+ cpriv->fifos.tx.count);
+ return -EINVAL;
+ }
/* calculate possible amount of RX fifos */
cpriv->fifos.rx.count = rx_memory_available / cpriv->fifos.rx.size;
@@ -138,10 +192,11 @@ static int mcp25xxfd_can_fifo_compute(struct mcp25xxfd_can_priv *cpriv)
/* now calculate effective number of rx-fifos. There are only 31 fifos
* available in total, so we need to limit ourselves
*/
- if (cpriv->fifos.rx.count > 31)
- cpriv->fifos.rx.count = 31;
+ if (cpriv->fifos.rx.count + cpriv->fifos.tx.count > 31)
+ cpriv->fifos.rx.count = 31 - cpriv->fifos.tx.count;
- cpriv->fifos.rx.start = 1;
+ cpriv->fifos.tx.start = 1;
+ cpriv->fifos.rx.start = cpriv->fifos.tx.start + cpriv->fifos.tx.count;
return 0;
}
@@ -170,6 +225,7 @@ static int mcp25xxfd_can_fifo_clear(struct mcp25xxfd_can_priv *cpriv)
int ret;
memset(&cpriv->fifos.info, 0, sizeof(cpriv->fifos.info));
+ memset(&cpriv->fifos.tx, 0, sizeof(cpriv->fifos.tx));
memset(&cpriv->fifos.rx, 0, sizeof(cpriv->fifos.rx));
/* clear FIFO config */
@@ -196,16 +252,31 @@ int mcp25xxfd_can_fifo_setup(struct mcp25xxfd_can_priv *cpriv)
if (ret)
return ret;
- cpriv->regs.tefcon = 0;
+ /* configure TEF */
+ if (cpriv->fifos.tef.count)
+ cpriv->regs.tefcon =
+ MCP25XXFD_CAN_TEFCON_FRESET |
+ MCP25XXFD_CAN_TEFCON_TEFNEIE |
+ MCP25XXFD_CAN_TEFCON_TEFTSEN |
+ ((cpriv->fifos.tef.count - 1) <<
+ MCP25XXFD_CAN_TEFCON_FSIZE_SHIFT);
+ else
+ cpriv->regs.tefcon = 0;
ret = mcp25xxfd_cmd_write(cpriv->priv->spi, MCP25XXFD_CAN_TEFCON,
cpriv->regs.tefcon);
if (ret)
return ret;
+ /* TXQueue disabled */
ret = mcp25xxfd_cmd_write(cpriv->priv->spi, MCP25XXFD_CAN_TXQCON, 0);
if (ret)
return ret;
+ /* configure FIFOS themselves */
+ ret = mcp25xxfd_can_fifo_setup_tx(cpriv);
+ if (ret)
+ return ret;
+
ret = mcp25xxfd_can_fifo_setup_rx(cpriv);
if (ret)
return ret;
@@ -219,10 +290,16 @@ int mcp25xxfd_can_fifo_setup(struct mcp25xxfd_can_priv *cpriv)
if (ret)
return ret;
+ /* setup tx_fifo_queue */
+ ret = mcp25xxfd_can_tx_queue_alloc(cpriv);
+ if (ret)
+ return ret;
+
return 0;
}
void mcp25xxfd_can_fifo_release(struct mcp25xxfd_can_priv *cpriv)
{
+ mcp25xxfd_can_tx_queue_free(cpriv);
mcp25xxfd_can_fifo_clear(cpriv);
}
@@ -23,6 +23,7 @@
#include "mcp25xxfd_can_int.h"
#include "mcp25xxfd_can_priv.h"
#include "mcp25xxfd_can_rx.h"
+#include "mcp25xxfd_can_tx.h"
#include "mcp25xxfd_cmd.h"
#include "mcp25xxfd_ecc.h"
@@ -80,7 +81,9 @@ static int mcp25xxfd_can_int_submit_frames(struct mcp25xxfd_can_priv *cpriv)
/* now submit the fifos */
for (i = 0; i < count; i++) {
fifo = queue[i].fifo;
- ret = mcp25xxfd_can_rx_submit_frame(cpriv, fifo);
+ ret = (queue[i].is_rx) ?
+ mcp25xxfd_can_rx_submit_frame(cpriv, fifo) :
+ mcp25xxfd_can_tx_submit_frame(cpriv, fifo);
if (ret)
return ret;
}
@@ -100,6 +103,9 @@ static int mcp25xxfd_can_int_submit_frames(struct mcp25xxfd_can_priv *cpriv)
}
out:
+ /* enable tx_queue if necessary */
+ mcp25xxfd_can_tx_queue_restart(cpriv);
+
return 0;
}
@@ -496,6 +502,9 @@ static int mcp25xxfd_can_int_error_handling(struct mcp25xxfd_can_priv *cpriv)
cpriv->can.can_stats.bus_off++;
can_bus_off(cpriv->can.dev);
}
+ } else {
+ /* restart the tx queue if needed */
+ mcp25xxfd_can_tx_queue_restart(cpriv);
}
return 0;
@@ -533,6 +542,16 @@ static int mcp25xxfd_can_int_handle_status(struct mcp25xxfd_can_priv *cpriv)
if (ret)
return ret;
+ /* handle aborted TX FIFOs */
+ ret = mcp25xxfd_can_tx_handle_int_txatif(cpriv);
+ if (ret)
+ return ret;
+
+ /* handle the TEF */
+ ret = mcp25xxfd_can_tx_handle_int_tefif(cpriv);
+ if (ret)
+ return ret;
+
/* handle error interrupt flags */
ret = mcp25xxfd_can_rx_handle_int_rxovif(cpriv);
if (ret)
@@ -26,10 +26,12 @@ struct mcp25xxfd_fifo {
struct mcp25xxfd_obj_ts {
s32 ts; /* using signed to handle rollover correctly when sorting */
u16 fifo;
+ s16 is_rx;
};
/* general info on each fifo */
struct mcp25xxfd_fifo_info {
+ u32 is_rx;
u32 offset;
u32 priority;
};
@@ -95,10 +97,18 @@ struct mcp25xxfd_can_priv {
/* infos on fifo layout */
+ /* TEF */
+ struct {
+ u32 count;
+ u32 size;
+ u32 index;
+ } tef;
+
/* info on each fifo */
struct mcp25xxfd_fifo_info info[32];
- /* extra info on rx fifo groups */
+ /* extra info on rx/tx fifo groups */
+ struct mcp25xxfd_fifo tx;
struct mcp25xxfd_fifo rx;
/* queue of can frames that need to get submitted
@@ -109,6 +119,9 @@ struct mcp25xxfd_can_priv {
*/
struct mcp25xxfd_obj_ts submit_queue[32];
int submit_queue_count;
+
+ /* the tx queue of spi messages */
+ struct mcp25xxfd_tx_spi_message_queue *tx_queue;
} fifos;
/* bus state */
@@ -163,7 +163,7 @@ static int mcp25xxfd_can_rx_read_frame(struct mcp25xxfd_can_priv *cpriv,
memset(rx->data + len, 0, ((net->mtu == CANFD_MTU) ? 64 : 8) - len);
/* add the fifo to the process queues */
- mcp25xxfd_can_queue_frame(cpriv, fifo, rx->ts);
+ mcp25xxfd_can_queue_frame(cpriv, fifo, rx->ts, true);
/* and clear the interrupt flag for that fifo */
return mcp25xxfd_cmd_write_mask(spi, MCP25XXFD_CAN_FIFOCON(fifo),
new file mode 100644
@@ -0,0 +1,620 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/* CAN bus driver for Microchip 25XXFD CAN Controller with SPI Interface
+ *
+ * Copyright 2019 Martin Sperl <kernel@martin.sperl.org>
+ *
+ * Based on Microchip MCP251x CAN controller driver written by
+ * David Vrabel, Copyright 2006 Arcom Control Systems Ltd.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/can/core.h>
+#include <linux/can/dev.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/netdevice.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+
+#include "mcp25xxfd_can.h"
+#include "mcp25xxfd_can_id.h"
+#include "mcp25xxfd_can_tx.h"
+#include "mcp25xxfd_cmd.h"
+#include "mcp25xxfd_regs.h"
+
+static struct mcp25xxfd_tx_spi_message *
+mcp25xxfd_can_tx_queue_first_spi_message(struct mcp25xxfd_tx_spi_message_queue *
+ queue, u32 *bitmap)
+{
+ u32 first = ffs(*bitmap);
+
+ if (!first)
+ return NULL;
+
+ return queue->fifo2message[first - 1];
+}
+
+static void mcp25xxfd_can_tx_queue_remove_spi_message(u32 *bitmap, int fifo)
+{
+ *bitmap &= ~BIT(fifo);
+}
+
+static void mcp25xxfd_can_tx_queue_add_spi_message(u32 *bitmap, int fifo)
+{
+ *bitmap |= BIT(fifo);
+}
+
+static void mcp25xxfd_can_tx_queue_move_spi_message(u32 *src, u32 *dest,
+ int fifo)
+{
+ mcp25xxfd_can_tx_queue_remove_spi_message(src, fifo);
+ mcp25xxfd_can_tx_queue_add_spi_message(dest, fifo);
+}
+
+static void mcp25xxfd_can_tx_spi_message_fill_fifo_complete(void *context)
+{
+ struct mcp25xxfd_tx_spi_message *msg = context;
+ struct mcp25xxfd_can_priv *cpriv = msg->cpriv;
+ struct mcp25xxfd_tx_spi_message_queue *q = cpriv->fifos.tx_queue;
+ unsigned long flags;
+
+ /* reset transfer length to without data (DLC = 0) */
+ msg->fill_fifo.xfer.len = sizeof(msg->fill_fifo.data.cmd) +
+ sizeof(msg->fill_fifo.data.header);
+
+ spin_lock_irqsave(&cpriv->fifos.tx_queue->lock, flags);
+
+ /* move to in_trigger_fifo_transfer */
+ mcp25xxfd_can_tx_queue_move_spi_message(&q->in_fill_fifo_transfer,
+ &q->in_trigger_fifo_transfer,
+ msg->fifo);
+
+ spin_unlock_irqrestore(&cpriv->fifos.tx_queue->lock, flags);
+}
+
+static void mcp25xxfd_can_tx_spi_message_trigger_fifo_complete(void *context)
+{
+ struct mcp25xxfd_tx_spi_message *msg = context;
+ struct mcp25xxfd_can_priv *cpriv = msg->cpriv;
+ struct mcp25xxfd_tx_spi_message_queue *q = cpriv->fifos.tx_queue;
+ unsigned long flags;
+
+ spin_lock_irqsave(&cpriv->fifos.tx_queue->lock, flags);
+
+ /* move to can_transfer */
+ mcp25xxfd_can_tx_queue_move_spi_message(&q->in_trigger_fifo_transfer,
+ &q->in_can_transfer,
+ msg->fifo);
+
+ spin_unlock_irqrestore(&cpriv->fifos.tx_queue->lock, flags);
+}
+
+static
+void mcp25xxfd_can_tx_message_init(struct mcp25xxfd_can_priv *cpriv,
+ struct mcp25xxfd_tx_spi_message *msg,
+ int fifo)
+{
+ const u32 trigger = MCP25XXFD_CAN_FIFOCON_TXREQ |
+ MCP25XXFD_CAN_FIFOCON_UINC;
+ const int first_byte = mcp25xxfd_cmd_first_byte(trigger);
+ u32 addr;
+
+ msg->cpriv = cpriv;
+ msg->fifo = fifo;
+
+ /* init fill_fifo */
+ spi_message_init(&msg->fill_fifo.msg);
+ msg->fill_fifo.msg.complete =
+ mcp25xxfd_can_tx_spi_message_fill_fifo_complete;
+ msg->fill_fifo.msg.context = msg;
+
+ msg->fill_fifo.xfer.tx_buf = msg->fill_fifo.data.cmd;
+ msg->fill_fifo.xfer.len = sizeof(msg->fill_fifo.data.cmd) +
+ sizeof(msg->fill_fifo.data.header);
+ spi_message_add_tail(&msg->fill_fifo.xfer, &msg->fill_fifo.msg);
+
+ addr = MCP25XXFD_SRAM_ADDR(cpriv->fifos.info[fifo].offset);
+ mcp25xxfd_cmd_calc(MCP25XXFD_INSTRUCTION_WRITE, addr,
+ msg->fill_fifo.data.cmd);
+
+ /* init trigger_fifo */
+ spi_message_init(&msg->trigger_fifo.msg);
+ msg->trigger_fifo.msg.complete =
+ mcp25xxfd_can_tx_spi_message_trigger_fifo_complete;
+ msg->trigger_fifo.msg.context = msg;
+
+ msg->trigger_fifo.xfer.tx_buf = msg->trigger_fifo.data.cmd;
+ msg->trigger_fifo.xfer.len = sizeof(msg->trigger_fifo.data.cmd) +
+ sizeof(msg->trigger_fifo.data.data);
+ spi_message_add_tail(&msg->trigger_fifo.xfer, &msg->trigger_fifo.msg);
+
+ mcp25xxfd_cmd_calc(MCP25XXFD_INSTRUCTION_WRITE,
+ MCP25XXFD_CAN_FIFOCON(fifo) + first_byte,
+ msg->trigger_fifo.data.cmd);
+ msg->trigger_fifo.data.data = trigger >> (8 * first_byte);
+
+ /* add to idle tx transfers */
+ mcp25xxfd_can_tx_queue_add_spi_message(&cpriv->fifos.tx_queue->idle,
+ fifo);
+}
+
+static
+void mcp25xxfd_can_tx_queue_manage_nolock(struct mcp25xxfd_can_priv *cpriv,
+ int state)
+{
+ struct net_device *net = cpriv->can.dev;
+
+ if (state == cpriv->fifos.tx_queue->state)
+ return;
+
+ /* start/stop netif_queue if necessary */
+ switch (cpriv->fifos.tx_queue->state) {
+ case MCP25XXFD_CAN_TX_QUEUE_STATE_RUNABLE:
+ switch (state) {
+ case MCP25XXFD_CAN_TX_QUEUE_STATE_RESTART:
+ case MCP25XXFD_CAN_TX_QUEUE_STATE_STARTED:
+ netif_wake_queue(net);
+ cpriv->fifos.tx_queue->state =
+ MCP25XXFD_CAN_TX_QUEUE_STATE_STARTED;
+ break;
+ }
+ break;
+ case MCP25XXFD_CAN_TX_QUEUE_STATE_STOPPED:
+ switch (state) {
+ case MCP25XXFD_CAN_TX_QUEUE_STATE_STARTED:
+ netif_wake_queue(net);
+ cpriv->fifos.tx_queue->state = state;
+ break;
+ }
+ break;
+ case MCP25XXFD_CAN_TX_QUEUE_STATE_STARTED:
+ switch (state) {
+ case MCP25XXFD_CAN_TX_QUEUE_STATE_RUNABLE:
+ case MCP25XXFD_CAN_TX_QUEUE_STATE_STOPPED:
+ netif_stop_queue(net);
+ cpriv->fifos.tx_queue->state = state;
+ break;
+ }
+ break;
+ default:
+ netdev_err(cpriv->can.dev, "Unsupported tx_queue state: %i\n",
+ cpriv->fifos.tx_queue->state);
+ break;
+ }
+}
+
+void mcp25xxfd_can_tx_queue_manage(struct mcp25xxfd_can_priv *cpriv, int state)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&cpriv->fifos.tx_queue->lock, flags);
+
+ mcp25xxfd_can_tx_queue_manage_nolock(cpriv, state);
+
+ spin_unlock_irqrestore(&cpriv->fifos.tx_queue->lock, flags);
+}
+
+void mcp25xxfd_can_tx_queue_restart(struct mcp25xxfd_can_priv *cpriv)
+{
+ u32 state = MCP25XXFD_CAN_TX_QUEUE_STATE_RESTART;
+ unsigned long flags;
+ u32 mask;
+
+ spin_lock_irqsave(&cpriv->fifos.tx_queue->lock, flags);
+
+ /* only move if there is nothing pending or idle */
+ mask = cpriv->fifos.tx_queue->idle |
+ cpriv->fifos.tx_queue->in_fill_fifo_transfer |
+ cpriv->fifos.tx_queue->in_trigger_fifo_transfer |
+ cpriv->fifos.tx_queue->in_can_transfer;
+ if (mask)
+ goto out;
+
+ /* move all items from transferred to idle */
+ cpriv->fifos.tx_queue->idle |= cpriv->fifos.tx_queue->transferred;
+ cpriv->fifos.tx_queue->transferred = 0;
+
+ /* and enable queue */
+ mcp25xxfd_can_tx_queue_manage_nolock(cpriv, state);
+out:
+ spin_unlock_irqrestore(&cpriv->fifos.tx_queue->lock, flags);
+}
+
+static
+int mcp25xxfd_can_tx_handle_int_tefif_fifo(struct mcp25xxfd_can_priv *cpriv)
+{
+ u32 tef_offset = cpriv->fifos.tef.index * cpriv->fifos.tef.size;
+ struct mcp25xxfd_can_obj_tef *tef =
+ (struct mcp25xxfd_can_obj_tef *)(cpriv->sram + tef_offset);
+ int fifo, ret;
+ unsigned long flags;
+
+ /* read the next TEF entry to get the transmit timestamp and fifo */
+ ret = mcp25xxfd_cmd_read_regs(cpriv->priv->spi,
+ MCP25XXFD_SRAM_ADDR(tef_offset),
+ &tef->id, sizeof(*tef));
+ if (ret)
+ return ret;
+
+ /* get the fifo from tef */
+ fifo = FIELD_GET(MCP25XXFD_CAN_OBJ_FLAGS_SEQ_MASK, tef->flags);
+
+ /* check that the fifo is valid */
+ spin_lock_irqsave(&cpriv->fifos.tx_queue->lock, flags);
+ if ((cpriv->fifos.tx_queue->in_can_transfer & BIT(fifo)) == 0)
+ netdev_err(cpriv->can.dev,
+ "tefif: fifo %i not pending - tef data: id: %08x flags: %08x, ts: %08x - this may be a problem with spi signal quality- try reducing spi-clock speed if this can get reproduced",
+ fifo, tef->id, tef->flags, tef->ts);
+ spin_unlock_irqrestore(&cpriv->fifos.tx_queue->lock, flags);
+
+ /* now we can schedule the fifo for echo submission */
+ mcp25xxfd_can_queue_frame(cpriv, fifo, tef->ts, false);
+
+ /* increment the tef index with wraparound */
+ cpriv->fifos.tef.index++;
+ if (cpriv->fifos.tef.index >= cpriv->fifos.tef.count)
+ cpriv->fifos.tef.index = 0;
+
+ /* finally just increment the TEF pointer */
+ return mcp25xxfd_cmd_write_mask(cpriv->priv->spi, MCP25XXFD_CAN_TEFCON,
+ MCP25XXFD_CAN_TEFCON_UINC,
+ MCP25XXFD_CAN_TEFCON_UINC);
+}
+
+static int
+mcp25xxfd_can_tx_handle_int_tefif_conservative(struct mcp25xxfd_can_priv *cpriv)
+{
+ u32 tefsta;
+ int ret;
+
+ /* read the TEF status */
+ ret = mcp25xxfd_cmd_read_mask(cpriv->priv->spi, MCP25XXFD_CAN_TEFSTA,
+ &tefsta, MCP25XXFD_CAN_TEFSTA_TEFNEIF);
+ if (ret)
+ return ret;
+
+ /* read the tef in an inefficient loop */
+ while (tefsta & MCP25XXFD_CAN_TEFSTA_TEFNEIF) {
+ /* read one tef */
+ ret = mcp25xxfd_can_tx_handle_int_tefif_fifo(cpriv);
+ if (ret)
+ return ret;
+
+ /* read the TEF status */
+ ret = mcp25xxfd_cmd_read_mask(cpriv->priv->spi,
+ MCP25XXFD_CAN_TEFSTA, &tefsta,
+ MCP25XXFD_CAN_TEFSTA_TEFNEIF);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+int mcp25xxfd_can_tx_handle_int_tefif(struct mcp25xxfd_can_priv *cpriv)
+{
+ unsigned long flags;
+ u32 finished;
+
+ if (!(cpriv->status.intf & MCP25XXFD_CAN_INT_TEFIF))
+ return 0;
+
+ spin_lock_irqsave(&cpriv->fifos.tx_queue->lock, flags);
+
+ /* compute finished fifos and clear them immediately */
+ finished = (cpriv->fifos.tx_queue->in_can_transfer ^
+ cpriv->status.txreq) &
+ cpriv->fifos.tx_queue->in_can_transfer;
+
+ spin_unlock_irqrestore(&cpriv->fifos.tx_queue->lock, flags);
+
+ return mcp25xxfd_can_tx_handle_int_tefif_conservative(cpriv);
+}
+
+static
+void mcp25xxfd_can_tx_fill_fifo_common(struct mcp25xxfd_can_priv *cpriv,
+ struct mcp25xxfd_tx_spi_message *smsg,
+ struct mcp25xxfd_can_obj_tx *tx,
+ int dlc, u8 *data)
+{
+ int len = can_dlc2len(dlc);
+
+ /* add fifo number as seq */
+ tx->flags |= smsg->fifo << MCP25XXFD_CAN_OBJ_FLAGS_SEQ_SHIFT;
+
+ /* copy data to tx->data for future reference */
+ memcpy(tx->data, data, len);
+
+ /* transform header to controller format */
+ mcp25xxfd_cmd_convert_from_cpu(&tx->id, sizeof(*tx) / sizeof(u32));
+
+ /* copy header + data to final location - we are not aligned */
+ memcpy(smsg->fill_fifo.data.header, &tx->id, sizeof(*tx) + len);
+
+ /* transfers to sram should be a multiple of 4 and be zero padded */
+ for (; len & 3; len++)
+ *(smsg->fill_fifo.data.header + sizeof(*tx) + len) = 0;
+
+ /* convert it back to CPU format */
+ mcp25xxfd_cmd_convert_to_cpu(&tx->id, sizeof(*tx) / sizeof(u32));
+
+ /* set up size of transfer */
+ smsg->fill_fifo.xfer.len = sizeof(smsg->fill_fifo.data.cmd) +
+ sizeof(smsg->fill_fifo.data.header) + len;
+}
+
+static
+void mcp25xxfd_can_tx_fill_fifo_fd(struct mcp25xxfd_can_priv *cpriv,
+ struct canfd_frame *frame,
+ struct mcp25xxfd_tx_spi_message *smsg,
+ struct mcp25xxfd_can_obj_tx *tx)
+{
+ int dlc = can_len2dlc(frame->len);
+
+ /* compute can id */
+ mcp25xxfd_can_id_to_mcp25xxfd(frame->can_id, &tx->id, &tx->flags);
+
+ /* setup flags */
+ tx->flags |= dlc << MCP25XXFD_CAN_OBJ_FLAGS_DLC_SHIFT;
+ tx->flags |= (frame->can_id & CAN_EFF_FLAG) ?
+ MCP25XXFD_CAN_OBJ_FLAGS_IDE : 0;
+ tx->flags |= (frame->can_id & CAN_RTR_FLAG) ?
+ MCP25XXFD_CAN_OBJ_FLAGS_RTR : 0;
+ if (frame->flags & CANFD_BRS)
+ tx->flags |= MCP25XXFD_CAN_OBJ_FLAGS_BRS;
+
+ tx->flags |= (frame->flags & CANFD_ESI) ?
+ MCP25XXFD_CAN_OBJ_FLAGS_ESI : 0;
+ tx->flags |= MCP25XXFD_CAN_OBJ_FLAGS_FDF;
+
+ /* and do common processing */
+ mcp25xxfd_can_tx_fill_fifo_common(cpriv, smsg, tx, dlc, frame->data);
+}
+
+static
+void mcp25xxfd_can_tx_fill_fifo(struct mcp25xxfd_can_priv *cpriv,
+ struct can_frame *frame,
+ struct mcp25xxfd_tx_spi_message *smsg,
+ struct mcp25xxfd_can_obj_tx *tx)
+{
+ /* set frame to valid dlc */
+ if (frame->can_dlc > 8)
+ frame->can_dlc = 8;
+
+ /* compute can id */
+ mcp25xxfd_can_id_to_mcp25xxfd(frame->can_id, &tx->id, &tx->flags);
+
+ /* setup flags */
+ tx->flags |= frame->can_dlc << MCP25XXFD_CAN_OBJ_FLAGS_DLC_SHIFT;
+ tx->flags |= (frame->can_id & CAN_EFF_FLAG) ?
+ MCP25XXFD_CAN_OBJ_FLAGS_IDE : 0;
+ tx->flags |= (frame->can_id & CAN_RTR_FLAG) ?
+ MCP25XXFD_CAN_OBJ_FLAGS_RTR : 0;
+
+ /* and do common processing */
+ mcp25xxfd_can_tx_fill_fifo_common(cpriv, smsg, tx, frame->can_dlc,
+ frame->data);
+}
+
+static struct mcp25xxfd_tx_spi_message *
+mcp25xxfd_can_tx_queue_get_next_fifo(struct mcp25xxfd_can_priv *cpriv)
+{
+ u32 state = MCP25XXFD_CAN_TX_QUEUE_STATE_RUNABLE;
+ struct mcp25xxfd_tx_spi_message_queue *q = cpriv->fifos.tx_queue;
+ struct mcp25xxfd_tx_spi_message *smsg;
+ unsigned long flags;
+
+ spin_lock_irqsave(&q->lock, flags);
+
+ /* get the first entry from idle */
+ smsg = mcp25xxfd_can_tx_queue_first_spi_message(q, &q->idle);
+ if (!smsg)
+ goto out_busy;
+
+ /* and move the fifo to next stage */
+ mcp25xxfd_can_tx_queue_move_spi_message(&q->idle,
+ &q->in_fill_fifo_transfer,
+ smsg->fifo);
+
+ /* if queue is empty then stop the network queue immediately */
+ if (!q->idle)
+ mcp25xxfd_can_tx_queue_manage_nolock(cpriv, state);
+out_busy:
+ spin_unlock_irqrestore(&q->lock, flags);
+
+ return smsg;
+}
+
+/* submit the can message to the can-bus */
+netdev_tx_t mcp25xxfd_can_tx_start_xmit(struct sk_buff *skb,
+ struct net_device *net)
+{
+ u32 state = MCP25XXFD_CAN_TX_QUEUE_STATE_STOPPED;
+ struct mcp25xxfd_can_priv *cpriv = netdev_priv(net);
+ struct mcp25xxfd_tx_spi_message_queue *q = cpriv->fifos.tx_queue;
+ struct mcp25xxfd_priv *priv = cpriv->priv;
+ struct spi_device *spi = priv->spi;
+ struct mcp25xxfd_tx_spi_message *smsg;
+ struct mcp25xxfd_can_obj_tx *tx;
+ unsigned long flags;
+ int ret;
+
+ /* invalid skb we can ignore */
+ if (can_dropped_invalid_skb(net, skb))
+ return NETDEV_TX_OK;
+
+ spin_lock_irqsave(&q->spi_lock, flags);
+
+ /* get the fifo message structure to process now */
+ smsg = mcp25xxfd_can_tx_queue_get_next_fifo(cpriv);
+ if (!smsg)
+ goto out_busy;
+
+ /* compute the fifo in sram */
+ tx = (struct mcp25xxfd_can_obj_tx *)
+ (cpriv->sram + cpriv->fifos.info[smsg->fifo].offset);
+
+ /* fill in message from skb->data depending on can2.0 or canfd */
+ if (can_is_canfd_skb(skb))
+ mcp25xxfd_can_tx_fill_fifo_fd(cpriv,
+ (struct canfd_frame *)skb->data,
+ smsg, tx);
+ else
+ mcp25xxfd_can_tx_fill_fifo(cpriv,
+ (struct can_frame *)skb->data,
+ smsg, tx);
+
+ /* submit the two messages asyncronously
+ * the reason why we separate transfers into two spi_messages is:
+ * * because the spi framework (currently) does add a 10us delay
+ * between 2 spi_transfers in a single spi_message when
+ * change_cs is set - 2 consecutive spi messages show a shorter
+ * cs disable phase increasing bus utilization
+ * (code reduction with a fix in spi core would be aprox.50 lines)
+ * * this allows the interrupt handler to start spi messages earlier
+ * so reducing latencies a bit and to allow for better concurrency
+ * * this separation - in the future - may get used to fill fifos
+ * early and reduce the delay on "rollover"
+ */
+ ret = spi_async(spi, &smsg->fill_fifo.msg);
+ if (ret)
+ goto out_async_failed;
+
+ ret = spi_async(spi, &smsg->trigger_fifo.msg);
+ if (ret)
+ goto out_async_failed;
+
+ spin_unlock_irqrestore(&q->spi_lock, flags);
+
+ can_put_echo_skb(skb, net, smsg->fifo);
+
+ return NETDEV_TX_OK;
+
+out_async_failed:
+ netdev_err(net, "spi_async submission of fifo %i failed - %i\n",
+ smsg->fifo, ret);
+
+out_busy:
+ mcp25xxfd_can_tx_queue_manage_nolock(cpriv, state);
+ spin_unlock_irqrestore(&q->spi_lock, flags);
+
+ return NETDEV_TX_BUSY;
+}
+
+/* submit the fifo back to the network stack */
+int mcp25xxfd_can_tx_submit_frame(struct mcp25xxfd_can_priv *cpriv, int fifo)
+{
+ struct mcp25xxfd_tx_spi_message_queue *q = cpriv->fifos.tx_queue;
+ struct mcp25xxfd_can_obj_tx *tx = (struct mcp25xxfd_can_obj_tx *)
+ (cpriv->sram + cpriv->fifos.info[fifo].offset);
+ int dlc = (tx->flags & MCP25XXFD_CAN_OBJ_FLAGS_DLC_MASK) >>
+ MCP25XXFD_CAN_OBJ_FLAGS_DLC_SHIFT;
+ unsigned long flags;
+
+ /* update counters */
+ cpriv->can.dev->stats.tx_packets++;
+ cpriv->can.dev->stats.tx_bytes += can_dlc2len(dlc);
+
+ spin_lock_irqsave(&cpriv->fifos.tx_queue->lock, flags);
+
+ /* release the echo buffer */
+ can_get_echo_skb(cpriv->can.dev, fifo);
+
+ /* move from in_can_transfer to transferred */
+ mcp25xxfd_can_tx_queue_move_spi_message(&q->in_can_transfer,
+ &q->transferred, fifo);
+
+ spin_unlock_irqrestore(&cpriv->fifos.tx_queue->lock, flags);
+
+ return 0;
+}
+
+static int
+mcp25xxfd_can_tx_handle_int_txatif_fifo(struct mcp25xxfd_can_priv *cpriv,
+ int fifo)
+{
+ struct mcp25xxfd_tx_spi_message_queue *q = cpriv->fifos.tx_queue;
+ unsigned long flags;
+ u32 val;
+ int ret;
+
+ ret = mcp25xxfd_cmd_read(cpriv->priv->spi,
+ MCP25XXFD_CAN_FIFOSTA(fifo), &val);
+ if (ret)
+ return ret;
+
+ ret = mcp25xxfd_cmd_write_mask(cpriv->priv->spi,
+ MCP25XXFD_CAN_FIFOSTA(fifo), 0,
+ MCP25XXFD_CAN_FIFOSTA_TXABT |
+ MCP25XXFD_CAN_FIFOSTA_TXLARB |
+ MCP25XXFD_CAN_FIFOSTA_TXERR |
+ MCP25XXFD_CAN_FIFOSTA_TXATIF);
+ if (ret)
+ return ret;
+
+ spin_lock_irqsave(&q->lock, flags);
+
+ can_get_echo_skb(cpriv->can.dev, fifo);
+ mcp25xxfd_can_tx_queue_move_spi_message(&q->in_can_transfer,
+ &q->transferred, fifo);
+
+ spin_unlock_irqrestore(&q->lock, flags);
+
+ cpriv->status.txif &= ~BIT(fifo);
+ cpriv->can.dev->stats.tx_aborted_errors++;
+
+ return 0;
+}
+
+int mcp25xxfd_can_tx_handle_int_txatif(struct mcp25xxfd_can_priv *cpriv)
+{
+ int i, f, ret;
+
+ if (!cpriv->status.txatif)
+ return 0;
+
+ /* process all the fifos with txatif flag set */
+ for (i = 0, f = cpriv->fifos.tx.start; i < cpriv->fifos.tx.count;
+ i++, f++) {
+ if (cpriv->status.txatif & BIT(f)) {
+ ret = mcp25xxfd_can_tx_handle_int_txatif_fifo(cpriv, f);
+ if (ret)
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+int mcp25xxfd_can_tx_queue_alloc(struct mcp25xxfd_can_priv *cpriv)
+{
+ struct mcp25xxfd_tx_spi_message *msg;
+ size_t size = sizeof(struct mcp25xxfd_tx_spi_message_queue) +
+ cpriv->fifos.tx.count * sizeof(*msg);
+ int i, f;
+
+ cpriv->fifos.tx_queue = kzalloc(size, GFP_KERNEL);
+ if (!cpriv->fifos.tx_queue)
+ return -ENOMEM;
+
+ spin_lock_init(&cpriv->fifos.tx_queue->lock);
+ spin_lock_init(&cpriv->fifos.tx_queue->spi_lock);
+
+ /* initialize the individual spi_message structures */
+ for (i = 0, f = cpriv->fifos.tx.start; i < cpriv->fifos.tx.count;
+ i++, f++) {
+ msg = &cpriv->fifos.tx_queue->message[i];
+ cpriv->fifos.tx_queue->fifo2message[f] = msg;
+ mcp25xxfd_can_tx_message_init(cpriv, msg, f);
+ }
+
+ return 0;
+}
+
+void mcp25xxfd_can_tx_queue_free(struct mcp25xxfd_can_priv *cpriv)
+{
+ kfree(cpriv->fifos.tx_queue);
+ cpriv->fifos.tx_queue = NULL;
+}
new file mode 100644
@@ -0,0 +1,86 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/* CAN bus driver for Microchip 25XXFD CAN Controller with SPI Interface
+ *
+ * Copyright 2019 Martin Sperl <kernel@martin.sperl.org>
+ */
+
+#ifndef __MCP25XXFD_CAN_TX_H
+#define __MCP25XXFD_CAN_TX_H
+
+#include <linux/spinlock.h>
+#include <linux/spi/spi.h>
+
+#include "mcp25xxfd_can_priv.h"
+
+/* structure of a spi message that is prepared and can get submitted quickly */
+struct mcp25xxfd_tx_spi_message {
+ /* the network device this is related to */
+ struct mcp25xxfd_can_priv *cpriv;
+ /* the fifo this fills */
+ u32 fifo;
+ /* the xfer to fill in the fifo data */
+ struct {
+ struct spi_message msg;
+ struct spi_transfer xfer;
+ struct {
+ u8 cmd[2];
+ u8 header[sizeof(struct mcp25xxfd_can_obj_tx)];
+ u8 data[64];
+ } data;
+ } fill_fifo;
+ /* the xfer to enable transmission on the can bus */
+ struct {
+ struct spi_message msg;
+ struct spi_transfer xfer;
+ struct {
+ u8 cmd[2];
+ u8 data;
+ } data;
+ } trigger_fifo;
+};
+
+struct mcp25xxfd_tx_spi_message_queue {
+ /* spinlock protecting the bitmaps
+ * as well as state and the skb_echo_* functions
+ */
+ spinlock_t lock;
+ /* bitmap of which fifo is in which stage */
+ u32 idle;
+ u32 in_fill_fifo_transfer;
+ u32 in_trigger_fifo_transfer;
+ u32 in_can_transfer;
+ u32 transferred;
+
+ /* the queue state as seen per controller */
+ int state;
+#define MCP25XXFD_CAN_TX_QUEUE_STATE_STOPPED 0
+#define MCP25XXFD_CAN_TX_QUEUE_STATE_STARTED 1
+#define MCP25XXFD_CAN_TX_QUEUE_STATE_RUNABLE 2
+#define MCP25XXFD_CAN_TX_QUEUE_STATE_RESTART 3
+
+ /* spinlock protecting spi submission order */
+ spinlock_t spi_lock;
+
+ /* map each fifo to a mcp25xxfd_tx_spi_message */
+ struct mcp25xxfd_tx_spi_message *fifo2message[32];
+
+ /* the individual messages */
+ struct mcp25xxfd_tx_spi_message message[];
+};
+
+int mcp25xxfd_can_tx_submit_frame(struct mcp25xxfd_can_priv *cpriv, int fifo);
+void mcp25xxfd_can_tx_queue_restart(struct mcp25xxfd_can_priv *cpriv);
+
+int mcp25xxfd_can_tx_handle_int_txatif(struct mcp25xxfd_can_priv *cpriv);
+int mcp25xxfd_can_tx_handle_int_tefif(struct mcp25xxfd_can_priv *cpriv);
+
+netdev_tx_t mcp25xxfd_can_tx_start_xmit(struct sk_buff *skb,
+ struct net_device *net);
+
+void mcp25xxfd_can_tx_queue_manage(struct mcp25xxfd_can_priv *cpriv, int state);
+
+int mcp25xxfd_can_tx_queue_alloc(struct mcp25xxfd_can_priv *cpriv);
+void mcp25xxfd_can_tx_queue_free(struct mcp25xxfd_can_priv *cpriv);
+
+#endif /* __MCP25XXFD_CAN_TX_H */